NFC: Monitor pn533 target mode

When receiving a DEP link down event, we should cancel all pending URBs
if we're activated as a target or if we're an initiator.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/nfc/pn533.c

@@ -343,6 +343,7 @@ struct pn533 {
 
 	u8 tgt_available_prots;
 	u8 tgt_active_prot;
+	u8 tgt_mode;
 };
 
 struct pn533_frame {
@@ -1158,6 +1159,8 @@ static int pn533_tm_get_data_complete(struct pn533 *dev, void *arg,
 	if (params_len > 0 && params[0] != 0) {
 		nfc_tm_deactivated(dev->nfc_dev);
 
+		dev->tgt_mode = 0;
+
 		kfree_skb(skb_resp);
 		return 0;
 	}
@@ -1245,6 +1248,8 @@ static int pn533_init_target_complete(struct pn533 *dev, void *arg,
 		return rc;
 	}
 
+	dev->tgt_mode = 1;
+
 	queue_work(dev->wq, &dev->tg_work);
 
 	return 0;
@@ -1397,6 +1402,12 @@ static int pn533_start_poll(struct nfc_dev *nfc_dev,
 		return -EBUSY;
 	}
 
+	if (dev->tgt_mode) {
+		nfc_dev_err(&dev->interface->dev,
+			    "Cannot poll while already being activated");
+		return -EBUSY;
+	}
+
 	if (tm_protocols) {
 		dev->gb = nfc_get_local_general_bytes(nfc_dev, &dev->gb_len);
 		if (dev->gb == NULL)
@@ -1725,7 +1736,15 @@ static int pn533_dep_link_down(struct nfc_dev *nfc_dev)
 
 	pn533_poll_reset_mod_list(dev);
 
-	pn533_deactivate_target(nfc_dev, 0);
+	if (dev->tgt_mode || dev->tgt_active_prot) {
+		pn533_send_ack(dev, GFP_KERNEL);
+		usb_kill_urb(dev->in_urb);
+	}
+
+	dev->tgt_active_prot = 0;
+	dev->tgt_mode = 0;
+
+	skb_queue_purge(&dev->resp_q);
 
 	return 0;
 }
@@ -1956,6 +1975,8 @@ static int pn533_tm_send_complete(struct pn533 *dev, void *arg,
 	if (params_len > 0 && params[0] != 0) {
 		nfc_tm_deactivated(dev->nfc_dev);
 
+		dev->tgt_mode = 0;
+
 		return 0;
 	}